It is well known that certain types of sausages such as frankfurters, are made on automatic stuffing machines. These machines stuff an uncooked sausage emulsion into a long tubular casing while simultaneously forming the casing into links. Typically, the casing is of a regenerated cellulosic and the individual links are formed by twisting the casing during stuffing. The individual links also may be formed by pinching the stuffed casing. In any event, the result is a string of links that may be up to 50 meters or more long. The string is processed to cook or cure the emulsion and then the casing is removed to produce individual sausages ready for retail packaging. Casings for use in making linked sausages generally are made of a pure regenerated cellulose and are produced in sizes which range from about 14.5 to 45 mm in diameter.
Peeling the cellulose casing from the sausages has presented particular problems to the art. In this respect, peeling aid solutions have been developed. These peeling aid solutions are applied to the inner wall of the casing by the casing manufacturer. Generally the solutions include compounds that create an aqueous film between the surface of the sausage and the casing. This film reduces the adhesion of the casing to the surface of the sausage and thus facilitates the peeling of the casing from the sausage. The effect of such peeling aids varies depending upon the particular formulation of the emulsion being stuffed and the processing conditions. Accordingly, it is not unusual for casing manufacturers to offer several different peeling treatments to accommodate the particular needs of its customers. The application of a peeling solution to the interior of the cellulose casing also requires additional materials and manufacturing steps that add to the casing cost.
U.S. Pat. No. 5,914,141 discloses application of proteases and lipases to the interior of the casing as a peeling aid. These enzymes degrade the stuffed sausage contents adjacent the inner surface of the casing so as to facilitate the subsequent peeling of the casing from the sausage. However, this may lead to a sausage that has a poor "bite" since the toughened cooked surface of the sasusage is degraded by the enzyme.
A typical method used by the sausage maker to remove the cellulose casing from the sausages is to run the string of links through a mechanical peeler. The peeler has a knife edge that longitudinally slits the casing. The string then passes over a perforated wheel connected to a vacuum source. The vacuum pulls the casing around the wheel and away from the sausages while the sausages are allowed to pass tangentially off the wheel. This separates the casing and frees the individual sausage links. The peeling apparatus also commonly exposes the string of sausages to steam to help loosen the casing from the sausage and facilitate peeling. Mechanical peelers of this type are shown in U.S. Pat. Nos. 3,698,973; 4,118,828; and 4,414,707 among others.
Mechanical peelers while comprising the present preferred method for peeling sausages, have several drawbacks. For example, the knife edge becomes dull and must be replaced periodically. If the knife edge is improperly positioned, it either will not cut through the casing or it may cut too deeply and score the sausage. If the casing is not cut, it can not be separated from the sausage. Thus, the knife edge must be critically controlled for bearing pressure and placement with respect to the casing surface in order to properly slit the casing without deeply scoring the surface of the sausage. The use of steam also is an objectionable part of the process even though it often is necessary for high percentage peeling. Use of steam results in high utility costs. The steam condenses and the free-standing water which results makes for an unsafe work environment. Also, the condensed steam collects on the peeled sausages and is a source of contamination. The problems caused by condensation is particularly acute if the steam peeling is conducted in a refrigerated environment.
Mechanical peelers and the use of casing treatments are not 100% effective. Often shards or bigger sections of casing remain on the peeled link that must be removed manually. Casing manufactures often add color or stripes to the cellulose casing to facilitate spotting the casing piece on the peeled sausage. These stripes or colors further add to the casing cost.
Disposal of the spent casing after removal from the sausages is another problem for the sausage manufacturer. Typically the spent casing is sent to a land fill. This is costly in terms of hauling and landfill charges.
In view of the drawbacks of methods currently in use for peeling cellulose casings from sausages, the need exists for an improved method for removing the casing from frankfurters that does not depend upon chemical easy peeling treatments applied to the inner surface of the casing to facilitate the peeling of the casing from the sausage. An improved method also is one that eliminates the need to contact the processed sausage with steam to facilitate the separation of the cellulose casing from the sausage. The need further exists for a method that eliminates the need for mechanical peelers to remove a cellulose casing from the sausages.
Accordingly, one object of the present invention is to provide an improved method for removing cellulose casings from sausages.
Another object of the present invention is to provide a method for removing cellulose casing from sausages that avoids the need for applying a product-specific easy peeling chemical treatment to the inner surface of the casing.
A further object of the present invention is to eliminate the use of mechanical peelers and steam assisted peeling to remove cellulose casings from frankfurter sausages and the like.
Yet another object is to provide a method of removing cellulose casing from sausages that eliminates the need for land filling the spent casing.